diff --git a/lib/matplotlib/backends/backend_pdf.py b/lib/matplotlib/backends/backend_pdf.py
index 7e3b600196bf..f4e254a0e9cb 100644
--- a/lib/matplotlib/backends/backend_pdf.py
+++ b/lib/matplotlib/backends/backend_pdf.py
@@ -2498,14 +2498,9 @@ class FigureCanvasPdf(FigureCanvasBase):
     ----------
     figure : `matplotlib.figure.Figure`
         A high-level Figure instance
-
     """
 
     fixed_dpi = 72
-
-    def draw(self):
-        pass
-
     filetypes = {'pdf': 'Portable Document Format'}
 
     def get_default_filetype(self):
diff --git a/lib/matplotlib/backends/backend_pgf.py b/lib/matplotlib/backends/backend_pgf.py
index da124a2dde69..49427b1f6fbf 100644
--- a/lib/matplotlib/backends/backend_pgf.py
+++ b/lib/matplotlib/backends/backend_pgf.py
@@ -952,14 +952,12 @@ def get_renderer(self):
         return RendererPgf(self.figure, None, dummy=True)
 
 
-class FigureManagerPgf(FigureManagerBase):
-    pass
+FigureManagerPgf = FigureManagerBase
 
 
 @_Backend.export
 class _BackendPgf(_Backend):
     FigureCanvas = FigureCanvasPgf
-    FigureManager = FigureManagerPgf
 
 
 def _cleanup_all():
diff --git a/lib/matplotlib/backends/backend_ps.py b/lib/matplotlib/backends/backend_ps.py
index 4c6848110237..958ad6204210 100644
--- a/lib/matplotlib/backends/backend_ps.py
+++ b/lib/matplotlib/backends/backend_ps.py
@@ -748,10 +748,6 @@ def swap_if_landscape(self, shape):
 
 class FigureCanvasPS(FigureCanvasBase):
     fixed_dpi = 72
-
-    def draw(self):
-        pass
-
     filetypes = {'ps': 'Postscript',
                  'eps': 'Encapsulated Postscript'}
 
diff --git a/lib/matplotlib/backends/backend_qt5.py b/lib/matplotlib/backends/backend_qt5.py
index 6b8a7ceb034b..46b684bba928 100644
--- a/lib/matplotlib/backends/backend_qt5.py
+++ b/lib/matplotlib/backends/backend_qt5.py
@@ -222,7 +222,6 @@ def __init__(self, figure):
         _create_qApp()
         super().__init__(figure=figure)
 
-        self.figure = figure
         # We don't want to scale up the figure DPI more than once.
         # Note, we don't handle a signal for changing DPI yet.
         figure._original_dpi = figure.dpi
diff --git a/lib/matplotlib/backends/backend_template.py b/lib/matplotlib/backends/backend_template.py
index 299a8aac9c1a..19c8c822274b 100644
--- a/lib/matplotlib/backends/backend_template.py
+++ b/lib/matplotlib/backends/backend_template.py
@@ -200,8 +200,7 @@ def draw(self):
 
     # If the file type is not in the base set of filetypes,
     # you should add it to the class-scope filetypes dictionary as follows:
-    filetypes = FigureCanvasBase.filetypes.copy()
-    filetypes['foo'] = 'My magic Foo format'
+    filetypes = {**FigureCanvasBase.filetypes, 'foo': 'My magic Foo format'}
 
     def print_foo(self, filename, *args, **kwargs):
         """
diff --git a/lib/matplotlib/backends/backend_wx.py b/lib/matplotlib/backends/backend_wx.py
index a01f57aa2bfe..6b94f8c399ac 100644
--- a/lib/matplotlib/backends/backend_wx.py
+++ b/lib/matplotlib/backends/backend_wx.py
@@ -512,12 +512,11 @@ class _FigureCanvasWxBase(FigureCanvasBase, wx.Panel):
 
     def __init__(self, parent, id, figure):
         """
-        Initialise a FigureWx instance.
+        Initialize a FigureWx instance.
 
-        - Initialise the FigureCanvasBase and wxPanel parents.
-        - Set event handlers for:
-          EVT_SIZE  (Resize event)
-          EVT_PAINT (Paint event)
+        - Initialize the FigureCanvasBase and wxPanel parents.
+        - Set event handlers for resize, paint, and keyboard and mouse
+          interaction.
         """
 
         FigureCanvasBase.__init__(self, figure)